Wavelength conversion component and light emitting device including the same

ABSTRACT

A wavelength conversion component includes a plurality of wavelength conversion members, a plurality of transmission type optical members respectively disposed on the wavelength conversion members, and a first member including a plurality of wall portions respectively located between adjacent ones of the wavelength conversion members. A light emitting device includes such wavelength conversion component.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Japanese Patent Application No.2019-014454 filed on Jan. 30, 2019, the disclosure of which is herebyincorporated by reference in its entirety.

BACKGROUND

The present disclosure relates to a wavelength conversion component anda light emitting device including the wavelength conversion component.

There are light emitting devices including a combination of asemiconductor light emitting element and a wavelength conversion member.

In such a light emitting device, for example, excitation light emittedfrom a blue light emitting diode or a blue semiconductor laser isirradiated to a phosphor-containing wavelength conversion member tocause wavelength-conversion to obtain yellow light. The yellow light ismixed with the blue light emitted from the blue light emitting diode orthe blue semiconductor laser to emit white light (for example, seeJapanese Unexamined Patent Application Publication No. 2017-224707).

SUMMARY

In such a light emitting device, a portion of the excitation light isabsorbed by the phosphor-containing wavelength conversion member, andlight wavelength-converted by the phosphor-containing wavelengthconversion member and another portion of excitation light that is notabsorbed by the phosphor-containing wavelength conversion member areincident on a transparent plate at an emission side, and are mixed andemitted from an outer surface of the transparent plate. Light emittedfrom the transparent plate can be broadly distributed, such that thelight emitted from the transparent plate includes a light emitted in thedirection perpendicular to the outer surface of the transparent plate, alight emitted in a direction parallel to the outer surface of thetransparent plate, and a light emitted in the direction between thesedirections. When the light emitted from the wavelength conversion memberhas a broad light distribution, utilization efficiency of the lightemitted from the light emitting device in a system using the lightemitting device tends to be reduced. One object of the present inventionis to provide a wavelength conversion component that can narrow thelight distribution of the light emitted from the wavelength conversionmember, and a light emitting device including the wavelength conversioncomponent.

A wavelength conversion component includes a plurality of wavelengthconversion members, a plurality of transmission type optical membersrespectively located on the wavelength conversion members, and a firstmember including a plurality of wall portions respectively locatedbetween adjacent ones of the wavelength conversion members.

According to certain embodiments of the present invention, a wavelengthconversion component that allows emitted light to have narrow lightdistribution, and a light emitting device including the wavelengthconversion component.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a schematic, vertical cross-sectional diagram showing awavelength conversion component according to a first embodiment.

FIG. 1B is a schematic plan diagram of the wavelength conversioncomponent of FIG. 1A.

FIG. 1C is a schematic, partially enlarged horizontal cross-sectionaldiagram of the plurality of wavelength conversion members and the firstmember according to a modification example of the wavelength conversioncomponent according to the first embodiment.

FIG. 1D is a schematic vertical cross-sectional diagram showingModification Example 1, which is another modification example, of thewavelength conversion component according to the first embodiment.

FIG. 1E is a schematic vertical cross-sectional diagram showingModification Example 2, which is yet another modification example, ofthe wavelength conversion component according to the first embodiment.

FIG. 1F is a schematic vertical cross-sectional diagram showingModification Example 3, which is yet another modification example, ofthe wavelength conversion component according to the first embodiment.

FIG. 1G is a schematic vertical cross-sectional diagram showing yetanother Modification Example 4, which is yet another modificationexample, of the wavelength conversion component according to the firstembodiment.

FIG. 1H is a schematic vertical cross-sectional diagram showingModification Example 5, which is yet another modification example, ofthe wavelength conversion component according to the first embodiment.

FIG. 2A is a schematic vertical cross-sectional diagram of thewavelength conversion component according to a second embodiment.

FIG. 2B is a schematic plan diagram of the wavelength conversioncomponent of FIG. 2A.

FIG. 2C is a schematic vertical cross-sectional diagram showing amodification example of the wavelength conversion component according tothe second embodiment.

FIG. 3 is a schematic vertical cross-sectional diagram of a lightemitting device according to a third embodiment.

FIG. 4 is a schematic diagram of a light emitting device according to afourth embodiment.

DETAILED DESCRIPTION

Certain embodiments of the present invention will be described below.The embodiments described below are intended as illustrative to give aconcrete form to technical ideas of the present invention, and the scopeof the invention is not limited to the embodiments described below. Thepresent invention may include combinations of the embodiments shownhereafter. Also, the sizes, materials, shapes, the relative positionsand the like of the members are occasionally shown exaggerated for easeof explanation. Furthermore, in the description below, the samedesignations or the same reference numerals denote the same or likemembers, and duplicative descriptions thereof will be appropriatelyomitted.

Light Emitting Device

A light emitting device includes a light emitting element and awavelength conversion component. The light emitting device may alsoinclude other members.

Light Emitting Element

The light emitting element is a generation source of excitation lightincident on the wavelength conversion component. Example of the lightemitting element include a semiconductor light emitting element, a lamp,a gas laser, or a combination of two or more of these can be employed,and more specifically, a light emitting diode, a semiconductor laser, amercury lamp, and an argon ion laser.

Wavelength Conversion Component

The wavelength conversion component includes a plurality of wavelengthconversion members, and a plurality of transmission type opticalelements each including a transmission type optical member. Thewavelength conversion members are arrayed spaced apart from each othervia corresponding wall portions of the first member.

-   -   Each transmission type optical member is placed on a respective        one of the wavelength conversion members. The wavelength        conversion component may further include a heat dissipation        member, with a plurality of the wavelength conversion members        arranged above the heat dissipation member, for example.

Wavelength Conversion Member

The wavelength conversion members are adapted to absorb excitationlight, and to generate light of a different wavelength from thewavelength of the excitation light. For the wavelength conversionmembers, for example, phosphor crystal particles, fluorescent dye,semiconductor microcrystal, or a light-transmissive solid or alight-transmissive liquid containing one or more of these materials canbe used.

Transmission Type Optical Member

The transmission type optical members are adapted to transmit lightemitted from each wavelength conversion member. An optical thin film canbe disposed on a surface of each transmission type optical member.

The transmission type optical members can solely constitute transmissiontype optical elements, or a combination of the transmission type opticalmembers and second members can constitute transmission type opticalelements. In other words, structural elements constituting thetransmission-type optical element can be solely the transmission typeoptical members disposed on the wavelength conversion members, or acombination of the transmission-type optical members and portions of thesecond member adjacent to the transmission type optical members. Thetransmission-type optical element has an array of the transmission-typeoptical members corresponding to the array of the wavelength conversionmembers. This structure allows for efficiently transmitting lightemitted from each wavelength conversion member. The array of thetransmission type optical members is preferably self-aligned with thearray of the wavelength conversion members. This allows for eliminatingnecessity for aligning the array of transmission type optical memberswith the array of the wavelength conversion members. For thetransmission type optical element, a lens, a light guide, or acombination of these can be used. Examples of the lens used for thetransmission type optical element include a convex lens, a rod lens,etc. For the light guide, for example, a collective body of pipes eachhaving the inner surface being a mirror surface, light pipes, step indexoptical fibers, or the like can be used. For example, structuralelements of the transmission-type optical element respectively includingthe transmission-type optical members and portions of the second memberadjacent to the transmission type optical members function as the lightpipes.

First Member, Second Member

The first member is configured to demarcate individual wavelengthconversion members.

In other words, the plurality of wavelength conversion members arelocated with the first member between adjacent wavelength conversionmembers.

The first member can have a structure in which a plurality of wallportions configured to demarcate individual wavelength conversionmembers are formed in a single body, defining a plurality ofthrough-holes, such that adjacent ones of the wavelength conversionmembers are spaced apart from each other via corresponding wall portionsof the first member. Also, the first member can have a structureincluding wall portions and upward facing surfaces to define a pluralityof recesses. The plurality of recesses are defined by wall portionsconfigured to demarcate individual wavelength conversion members, and byupward facing surfaces of the first member configured to cover lowersurfaces of the plurality of wavelength conversion members. The firstmember can also be made of a light-transmissive material. Also, thefirst member can be made a light reflective material or a light blockingmaterial. Alternatively, the first member can be made of a combinationof a light-transmissive material, a light reflective material, and alight shielding material.

The second member is disposed to separate the plurality of transmissiontype optical members. The second member has a refractive index lowerthan that of the transmission type optical member. With such arefractive index, light propagated in the transmission type opticalmember can be easily totally-reflected on a surface of the secondmember. Also, when the transmission type optical member is a rod lens,the transmission type optical member may not include the second member.

Different materials or the same material can be used for a material ofthe first member and a material of the second member. For example, wallportions of the first member can extend upward with respect to the upperend of the wavelength conversion member, and the transmission typeoptical members can be spaced apart from each other via correspondingextending wall portions of the first member. This allows the array ofthe transmission type optical members to be self-aligned to the array ofthe wavelength conversion members.

Heat Dissipation Member

The heat dissipation member propagates heat that is generated in thewavelength conversion members, and dissipates heat to outside of thewavelength conversion members. The heat dissipation member is disposedbelow the plurality of wavelength conversion members to cover theplurality of wavelength conversion members. Metal materials such as Cu,Al, diamond, silicon carbide (SiC), aluminum nitride (AlN), sapphire(Al₂O₃), etc., can be suitably used for a material of theheat-dissipating member.

Other Members

The light emitting device can further include members other than thelight emitting element and the wavelength conversion component. Thelight emitting device can further include, for example, a casing of thelight emitting device, a drive power supply of the light emittingelement, an optical member, etc.

First Embodiment

The structure of a wavelength conversion component 100 of a firstembodiment will be described below with reference to FIG. 1A and FIG.1B.

For wavelength conversion members 10, phosphor crystal particles,fluorescent glass particles, phosphor fine particle dispersed resin,semiconductor fine particle dispersed resin, fluorescent-dye-containingresin, fluorescent-dye-containing liquid, etc., can be used. Examples ofthe phosphor crystal particles include various types of phosphor crystalparticles such as columnar ZnO crystal particles, YAG crystal particles,CASN crystal particles, α-SiAlON crystal particles, etc. Examples of thefluorescent glass particles include glass that contains various types ofrare earth elements (Tb, Eu, Pr, etc., for example). Examples of thephosphor-fine-particle-dispersed resin include a silicone resin in whichperovskite quantum dots, ZnO fine particles, YAG fine particles, CASNfine particles, SiAlON fine particles, silicate phosphor fine particles,or the like are dispersed. Examples of thesemiconductor-fine-particle-dispersed resin include a silicone resin inwhich CdSe/ZnS core shell type semiconductor quantum dots, InP/ZnS coreshell type semiconductor quantum dots, AgInS/GaS core shell typesemiconductor quantum dots, or the like are disposed. Examples of thefluorescent-dye-containing resin include acrylic resin in which afluorescent dye such as rhodamine is dispersed. Examples of thefluorescent-dye-containing liquid include silicone oil in which afluorescent dye such as rhodamine is dispersed. The material, shape, anddimensions of the wavelength conversion members 10 can be selected asappropriate according to the design of the wavelength conversioncomponent 100.

For the wavelength conversion members 10, for example, columnar crystalparticles of β-sialon which is a green phosphor (diameter ofapproximately 5 μm×length of approximately 35 μm) can be preferablyused. When blue excitation light is irradiated on the columnar crystalparticles of green phosphor, green light is emitted from both endsurfaces of the columnar crystal along the long axis of the columnarcrystal particles with an intensity greater than an intensity of greenlight emitted from lateral surfaces of the columnar crystal particles.Because the refractive index of the phosphor crystals is higher than therefractive index of material surrounding the phosphor crystals, whengreen light generated in the inside of the phosphor crystal is incidenton the lateral surface of the phosphor crystal at an angle greater thanthe critical angle, the incident green light is totally reflected andincident on an end surface of the phosphor crystal in the long axisdirection at an angle smaller than the critical angle, and accordinglyeasily emitted to outside the phosphor crystals.

For the wavelength conversion members 10, two or more types of phosphorcrystal particles, fluorescent glass particles, phosphor fine particledispersed resin, semiconductor fine particle dispersed resin,fluorescent dye-containing resin, fluorescent dye-containing liquid,semiconductor multilayer film, or the like may be used. For example, thewavelength conversion members 10 can contain YAG crystal particles as afirst wavelength conversion member 11, and CASN crystal particles as asecond wavelength conversion member 12, and as shown in FIG. 1C, thefirst and second wavelength-conversion members 11 and 12 can be arrangedin a mosaic arrangement. Furthermore, the wavelength conversion members10 may further include a third wavelength conversion member, a fourthwavelength conversion member, a fifth wavelength conversion member,and/or further additional wavelength conversion members. The number oftypes, material, shape, dimension, and arrangement of the wavelengthconversion members 10 can be selected as appropriate according to thedesign of the wavelength conversion component 100.

For a first member 20, a plate made of transparent glass, transparentresin, white resin, or the like, defining a plurality of recesses can beused. In the present specification, “transparent glass” refers to glasswith high transparency, such as optical glass, for example, quartzglass, crown glass, or flint glass. Also, “transparent resin” refers toresin with high transparency, such as epoxy resin, silicone resin,polymethyl methacrylate resin, polyethylene terephthalate resin, orpolycarbonate resin. Also, “white resin” refers to a transparent resincontaining dispersed fine particles having a refractive index differentfrom that of the transparent resin, such as fine particles includingsilica, calcium carbonate, barium sulfate, titanium oxide, hollowparticles, resin beads, or the like, which are called a light diffusingagent. The material, shape, and dimensions of the first member 20 can beselected as appropriate according to the design of the wavelengthconversion component 100.

When the wavelength conversion members 10 are housed in respective onesof the plurality of recesses of the first member 20, the wavelengthconversion members 10 are spaced apart from each other via correspondingwall portions of the first member 20. Alternatively, the wavelengthconversion members 10 and the corresponding portions of the first member20 may be arranged in a prescribed pattern by first preparing theplurality of the wavelength conversion members 10 each surrounded by arespective member constituting a part of the first member 20, and thengathering and bonding the respective members to each other.

Examples of the first member 20 include a quartz glass plate, which is atransparent glass, defining a plurality of recesses with a honeycombshape (i.e., arranged in an equilateral triangle lattice) formed in asurface of the quartz glass plate using a micro-processing techniquethat employs photolithography and reactive ion etching. For example,each of the recesses has a depth of 50 μm and a hexagonal shape in aplan view as shown in FIG. 1B, and the wall portions defining therecesses have a thickness of 1 μm. Furthermore, for example, thedistance between two opposite walls in each of the recesses is 6 μm.That is, the arrangement interval of the plurality of recesses can be 7μm. The first member, which includes walls defining the recesses, mayextend upward with respect to the upper ends of the wavelengthconversion members. In each recess, for example, a respective one ofβ-sialon columnar crystal particles (diameter of approximately 5μm×length of approximately 35 μm) is housed. In this case, theexcitation light 70 is transmitted from below the first member 20, andis incident on lower portions and lateral portions of the β-sialoncolumnar crystal particles, which are the wavelength conversion members10. Each of the β-sialon columnar crystal particles is a single crystalparticle rather than aggregated particles. Accordingly, no interface ispresent inside each β-sialon columnar crystal particle, which allowsreduction of light scattering, and the β-sialon columnar crystalparticles has good heat conduction. Thus, the β-sialon columnar crystalparticles are preferably employed. A region extending over a depth of 15μm on a side of the upward-facing opening of each recess forms a portionof a light pipe 30 that extends upward beyond the upper end of thewavelength conversion member 10. In the embodiment shown in FIG. 1A, thelight pipes 30 include transmission type optical members 31 and portionsof the first member, which also serve as the second members 32.

While each recess has a hexagonal shape in a plan view in thedescription above, each recess may have a triangular shape, a squareshape, an oval shape, a circular shape, etc., in a plan view. In a planview, each recess preferably has a planar shape that allows a planarconfiguration of multiple repetitions of the planar shape closely fittedtogether, which allows for increasing the density of the wavelengthconversion members 10.

Also, for example, for the first member 20, a honeycomb structureincluding walls with high reflectance (a honeycomb structure made ofwhite thermosetting resin, for example) can be employed. When employinga honeycomb structure, the excitation light 70 is emitted from below thefirst member 20 and is incident on the wavelength conversion members 10,and light emitted laterally from the wavelength conversion members 10 isreflected by the first member 20. That is, light emitted from thewavelength conversion component 100 is constituted of light emittedupward from the wavelength conversion members 10. Accordingly, forexample, when the plurality of wavelength conversion members 10 containtwo or more types of wavelength conversion member, variation in emissioncolor according to the emission angle of the emitted light can bereduced. Also, absorption or scattering of light emitted from one of thewavelength conversion members by another wavelength conversion membercan be reduced.

When manufacturing the first member 20, a processing technique can beselected as appropriate according to the material, shape, dimensions,etc. of the first member 20, and various processing techniques can beemployed in combination. Examples of the processing technique includephotolithography and reactive ion etching, compression molding,nano-imprinting, anodic oxidation, a technique in which a collectivebody of glass tubes is fused, stretched and sliced, etc.

For example, the wavelength conversion component according to thepresent embodiment allows for narrowing the light distribution of theemitted light using the light pipes 30 including the transmission typeoptical members 31 and the second member 32.

For the transmission type optical members 31, for example, highrefractive index silicone resin rods (refractive index: 1.57) can beused. For the second member 32, for example, a quartz glass wall(refractive index: 1.46) can be used. The high refractive index siliconeresin rods serving as the transmission type optical members 31 aredisposed on respective columnar crystal particles of β-sialon whichserve as the wavelength conversion members 10. The light pipes are madeof the quartz glass wall and the high refractive index silicone resin.The green light emitted from the columnar crystal particles of β-sialonare transmitted through the interior of the high refractive indexsilicone resin rods, reflected at the interface with the quartz glasswall, and emitted from upper surfaces of the high refractive indexsilicone resin rods. Because the numerical aperture of the light pipesis determined according to the refractive index of the high refractiveindex silicone resin rods and the refractive index of the quartz glasswall, light distribution of light emitted from the light pipe 30 can benarrower than that when including no light pipe 30 including thetransmission type optical member 31 and the second member 32.

Alternatively, for example, as shown in FIG. 1D, a convex lens 311 maybe disposed on each of the wavelength conversion members 10. Furtheralternatively, for example as shown in FIG. 1E, a transmission typeoptical element 301 that includes the second member 32 and atransmission type optical member 312, in which a columnarlight-transmissive member and a convex lens are integrated, may bedisposed on each of the wavelength conversion members 10. Still furtheralternatively, for example as shown in FIG. 1F, the rod lens 312 may bedisposed on each of the wavelength conversion members 10. Yet furtheralternatively, for example, a transmission type optical element 302including a lens 313, such as an Sift spherical lens, disposed on thelight pipe 30 may be disposed on each of the wavelength conversionmembers 10 (FIG. 1G). Even further alternatively, for example, a groupof transmission type optical elements 303 including a microlens array314 and a plurality of the light pipes 30 may be disposed on theplurality of wavelength conversion members 10 (FIG. 1H). In thesemodification examples, the group of the transmission type opticalelements include an array of transmission type optical memberscorresponding to the array of the wavelength conversion members.

When the wavelength conversion member 10 absorbs the excitation lightand emits light of a wavelength longer than the excitation light, theenergy corresponding to the Stokes shift is generated as heat. When theheat is accumulated in the wavelength conversion member 10 to increasethe temperature of the wavelength conversion member 10, the wavelengthconversion efficiency of the wavelength conversion member 10 generallydecreases. For reducing such decrease in wavelength conversionefficiency, it is effective to dispose the wavelength conversion member10 on the heat dissipation member 40.

Also, in the wavelength conversion component according to the presentembodiment, the wavelength conversion members 10 can be spaced apartfrom each other via corresponding wall portions of the first member, andthe transmission type optical members 31 may be spaced apart from eachother via corresponding wall portions of the second member. As shown inFIG. 1A and FIG. 1B, the first member 20 and the second member 32 can bemade of the same material, or the second member 32 can be formed on thefirst member 20 using a material different from a material of the firstmember 20. As shown in FIG. 1B, the upper surface of the transmissiontype optical member 31 has a hexagonal shape, and the second member 32has a honeycomb structure as in the first member 20 described above. Forexample, a transparent substrate with good thermal conductivity(sapphire substrate, AlN substrate, SiC substrate, diamond substrate,quartz glass, etc.) can be used for the first member 20, and white resincan be used for the second member 32.

Also, for example as shown in FIG. 1E, when using the same resin withhigh transparency for the first member 20 and the second member 32, atransparent substrate with good thermal conductivity (e.g., sapphiresubstrate, AlN substrate, SiC substrate, diamond substrate, or acombination of two or more of these) can be bonded below the secondmember 32 and the plurality of the wavelength conversion members 10, toserve as the heat dissipation member 40.

Second Embodiment

The structure of a wavelength conversion component 200 according to asecond embodiment will be described hereafter with reference to FIG. 2Aand FIG. 2B.

The wavelength conversion component 200 has a semiconductor multilayerfilm 16 that includes a quantum well layer 161. The semiconductormultilayer film 16 can also include an excitation light absorption layer162, a composition gradient layer 163, and a carrier confinement layer164 that are located at a lower side, an upper side, or both upper andlower sides of the quantum well layer 161. It is also preferable to havea total reflection mirror 165 at the lower side of the semiconductormultilayer film. For the total reflection mirror, a metal layer of Ag,etc., or a dielectric multilayer film can be used. The light emissionspectrum of light emitted from the quantum well layer 161 has a narrowhalf band width. The wavelength conversion component 200 can bepreferably used for, for example, an application to a light source for aprojector that uses a color filter.

For a first member 201, for example, an SiO₂ film can be used.Alternatively, a compound member of an SiO₂ film and an air layer, or acompound member of an SiO₂ film and a solder layer, etc., can be usedfor the first member 201.

For a transmission-type optical element 304, for example as shown inFIG. 2A, light pipes (example of transmission-type optical members inthis embodiment) each having a sapphire core 33 (refractive index: 1.77)and a transparent silicone resin cladding 34 (refractive index: 1.57)surrounding the sapphire core 33 can be used. The light pipe 304disposed on the semiconductor multilayer film 16 that functions as theplurality of wavelength conversion members can be arranged in, forexample, a square lattice form as shown in FIG. 2B.

Examples of the heat dissipation member 40 include a gold plated copperblock.

The reflective type wavelength conversion component 200 according to thesecond embodiment can be formed, for example, as described below. With asapphire substrate serving as the growth substrate for growing thesemiconductor multilayer film 16, the nitride semiconductor multilayerfilm 16 containing the quantum well layer 161 configured to emit greenlight is crystal-grown using an MOCVD method. Thereafter, the totalreflection mirror 165 is formed on the semiconductor multilayer film 16.Grooves are formed to divide the semiconductor multilayer film 16 andthe total reflection mirror 165 into predetermined regions, and thegrooves are covered by the SiO₂ film, to form the first member 201. Forformation of the total reflection mirror, the grooves, and the SiO₂film, a general semiconductor wafer process (photolithography,sputtering, CVD, dry etching, etc.) can be employed. Then, the sapphiresubstrate with the semiconductor multilayer film 16 and the totalreflection mirror 165 is inverted, and is bonded to the gold platedcopper block such that a total reflection mirror 165 faces the goldplated copper block. After polishing the sapphire substrate to have apredetermined thickness, the groove is formed to demarcate the sapphiresubstrate, forming a plurality of the sapphire cores 33. A transparentsilicone resin is injected in the groove and cured to obtain thecladding 34, so that the transmission type optical element including aplurality of the light pipes 304 is obtained. The transmission typeoptical element has an array of light pipes corresponding to the arrayof the divided semiconductor multilayer films 16.

Also, for example, as a light pipe 305, which is a structural element ofthe transmission type optical element, as shown in FIG. 2C, the lightpipe in which each of the plurality of sapphire cores 33 is surroundedby a respective one of claddings 35 having a wedge shape in across-sectional view may be used. In each of the grooves dividing thesemiconductor multilayer film 16 and the total reflection mirror 165, adeep groove is formed in the sapphire substrate, and the cladding 35 isdisposed to extend to the sapphire substrate. This allows the array ofthe transmission type optical members to be self-aligned to the array ofthe wavelength conversion members. The cladding 35 is a portion of thefirst member 201 that extends upward of the interface between thesemiconductor multilayer film 16, which functions as the wavelengthconversion members, and the sapphire substrate. Such a structure causesthe sapphire core 33 to have a shape that expands upward (invertedfrustum pyramid shape), which allows for narrowing distribution of thelight emitted from the reflective type wavelength conversion component200, and thus is preferable. For forming the deep grooves in thesapphire substrate, for example, laser processing such as laser inducedbackside wet etching (LIBWE) can be employed.

Third Embodiment

The structure of a light emitting device 300 according to a thirdembodiment will be described below with reference to FIG. 3.

The light emitting device 300 includes a light emitting element 50. Forthe light emitting element 50, for example, a flip-chip type blue lightemitting diode chip that includes an upper surface, a lower surface, ann side pad electrode 531 and a p side pad electrode 532 that aredisposed on the lower surface, a sapphire substrate 510 on the uppersurface, and a semiconductor multilayer film 520, which includes an ntype semiconductor layer 521, a blue light emitting layer 522, and a ptype semiconductor layer 523 between the p side pad electrode 532 andthe sapphire substrate 510.

The light emitting device 300 includes the wavelength conversion element100 according to the first embodiment, for example. The wavelengthconversion component 100 is bonded to the sapphire substrate of the topsurface of one light emitting element 50, for example.

The light emitting device 300 can further include members other thanmembers described above. For example, the light emitting device 300 canfurther include light shielding lateral walls 60 that cover lateralsurfaces of the light emitting element 50 and lateral surfaces of thewavelength conversion component 100. Examples of a material of the lightblocking side wall 60 include a white resin and a black resin.

In the light emitting device 300, the excitation light 70 from a singlelight emitting element 50 is incident on the wavelength conversioncomponent 100. The excitation light 70 is divided and incident oncorresponding ones of a plurality of the wavelength conversion members10, and a portion or all of the incident light is absorbed by thewavelength conversion members 10. Thereafter, light wavelength-convertedby the phosphor-containing wavelength conversion member is emitted fromthe corresponding wavelength conversion members 10 and transmittedthrough the light pipe 30 on the corresponding wavelength conversionmember 10, and is then emitted from the wavelength conversion component100. When light emitted from the corresponding wavelength conversionmembers 10 is transmitted through the light pipe 30, distribution oflight is narrowed.

Fourth Embodiment

The structure of a reflective type light emitting device 400 accordingto a fourth embodiment will be described with reference to FIG. 4.

The reflective type light emitting device 400 includes a light emittingelement 55. For the light emitting element 55, for example, a bluesemiconductor laser can be used.

The reflective type light emitting device 400 includes the wavelengthconversion component 200 according to the second embodiment, forexample. An excitation light 70 from the blue semiconductor laser istransmitted through a convex lens 80 and a dichroic prism 90 andcondensed by a convex lens 85, and is incident on the wavelengthconversion component 200, for example. Aligning the NA of the convexlens 85 and the NA of the light pipe with each other allows forefficiently utilizing light wavelength-converted by thephosphor-containing wavelength conversion member.

The reflective type light emitting device 400 can further includemembers other than members described above. For example, the reflectivetype light emitting device 400 can further include lenses, prisms,mirrors, dichroic mirrors, wave plates, a case, etc.

In the reflective type light emitting device 400, excitation light 70from a single light emitting element 55 is incident on the wavelengthconversion component 200. The excitation light 70 is divided andincident on corresponding ones of the plurality of wavelength conversionmembers 10, and a portion or all of the incident light is absorbed bythe corresponding wavelength conversion members 10. Thereafter, lightwavelength-converted by the phosphor-containing wavelength conversionmember is emitted from the corresponding wavelength conversion members10 and transmitted through the light pipe on the wavelength conversionmembers 10, and is then emitted from the wavelength conversion component200. When the light emitted from the corresponding wavelength conversionmembers 10 is transmitted through the light pipe, the light distributionis narrowed.

The wavelength conversion component and the light emitting deviceaccording to certain embodiments of the present invention can be usedfor various applications, such as various types of light sources foron-board use including head lights, a light source for a projectordevice, a light source for backlight device for a liquid crystal displaydevice, a signal light device, various types of illumination devices,etc.

It is to be understood that although the present invention has beendescribed with regard to preferred embodiments thereof, various otherembodiments and variants may occur to those skilled in the art, whichare within the scope and spirit of the invention, and such otherembodiments and variants are intended to be covered by the followingclaims.

What is claimed is:
 1. A wavelength conversion component comprising: aplurality of wavelength conversion members; a plurality of transmissiontype optical members respectively located on the wavelength conversionmembers; and a first member made of glass or resin and comprising aplurality of wall portions respectively located between adjacent ones ofthe wavelength conversion members, the wall portions extending upwardwith respect to upper ends of the wavelength conversion members suchthat the transmission type optical members are spaced apart from eachother via the wall portions, wherein the transmission type opticalmembers have a refractive index greater than a refractive index of thefirst member.
 2. The wavelength conversion component according to claim1, further comprising a heat dissipation member directly in contact withthe wavelength conversion members on a side opposite to the transmissiontype optical members.
 3. The wavelength conversion component accordingto claim 1, further comprising a heat dissipation member covering thewavelength conversion members on a side opposite to the transmissiontype optical members.
 4. The wavelength conversion component accordingto claim 1, wherein the wavelength conversion members include a firstwavelength conversion member and a second wavelength conversion memberthat are made of different materials.
 5. The wavelength conversioncomponent according to claim 2, wherein the wavelength conversionmembers include a first wavelength conversion member and a secondwavelength conversion member that are made of different materials. 6.The wavelength conversion component according to claim 3, wherein thewavelength conversion members include a first wavelength conversionmember and a second wavelength conversion member that are made ofdifferent materials.
 7. A light emitting device comprising: thewavelength conversion component according to claim 1; and a lightemitting element disposed below the wavelength conversion component. 8.A light emitting device comprising: the wavelength conversion componentaccording to claim 2; and a light emitting element disposed below thewavelength conversion component.
 9. A light emitting device comprising:the wavelength conversion component according to claim 3; and a lightemitting element disposed below the wavelength conversion component. 10.A light emitting device comprising: the wavelength conversion componentaccording to claim 4; and a light emitting element disposed below thewavelength conversion component.